[openexr] Replace buf_to_file with IStream (#4094)

* Add a working skeleton for OpenEXR fuzzers.

* added openexr fuzzers, updated build script to include them

* cleaned up bash loop

* [openexr] Replace buf_to_file with StdISStream.

Version 2.5.0 of OpenEXR added a StdISStream class that turns
a std::string into an Imf::IStream, which can be used instead of
filenames when opening an OpenEXR image.  This commit adds code which
wraps the fuzzer input into a StdISStream, which enables us to remove
the hacky buf_to_file function.

* updated deepscanlines_fuzzer to use IStream instead of filenames

* replace "/work" with  in build.sh

* Reformat CMake settings, and also prevent building utils and examples.

* Reformat and change names in build.sh.

* Omit the version prefix when building OpenEXR and IlmBase libraries.

* updated final two fuzzers to use istream

* fixed additional conflict in project.yaml

* get header size from input

* increased header size

* Fix argument types in readFileSingle

Co-authored-by: Michael Jezierny <mtjz@google.com>
Co-authored-by: Abhishek Arya <inferno@chromium.org>

4 files changed, 56 insertions, 132 deletions

diff --git a/projects/openexr/openexr_deepscanlines_fuzzer.cc b/projects/openexr/openexr_deepscanlines_fuzzer.cc
index 9682dea0f..ff77d8e45 100644
--- a/projects/openexr/openexr_deepscanlines_fuzzer.cc
+++ b/projects/openexr/openexr_deepscanlines_fuzzer.cc
@@ -24,6 +24,9 @@
 #include <ImfDeepScanLineInputPart.h>
 #include <ImfMultiPartInputFile.h>
 #include <ImfNamespace.h>
+#include <ImfStdIO.h>
+
+#include <fuzzer/FuzzedDataProvider.h>
 
 namespace IMF = OPENEXR_IMF_NAMESPACE;
 using namespace IMF;
@@ -108,10 +111,11 @@ static void readFile(T *inpart) {
   }
 }
 
-static void readFileSingle(const char filename[]) {
+static void readFileSingle(IStream& is, uint64_t width, uint64_t height) {
   DeepScanLineInputFile *file = NULL;
+  Header header(width, height);
   try {
-    file = new DeepScanLineInputFile(filename, 0);
+    file = new DeepScanLineInputFile(header, &is, EXR_VERSION, 0);
   } catch (...) {
     return;
   }
@@ -124,10 +128,10 @@ static void readFileSingle(const char filename[]) {
   delete file;
 }
 
-static void readFileMulti(const char filename[]) {
+static void readFileMulti(IStream& is) {
   MultiPartInputFile *file = NULL;
   try {
-    file = new MultiPartInputFile(filename, 0);
+    file = new MultiPartInputFile(is, 0);
   } catch (...) {
     return;
   }
@@ -151,35 +155,19 @@ static void readFileMulti(const char filename[]) {
 
 }  // namespace
 
-// from cl/164883104
-static char *buf_to_file(const char *buf, size_t size) {
-  char *name = strdup("/dev/shm/fuzz-XXXXXX");
-  int fd = mkstemp(name);
-  if (fd < 0) {
-    perror("open");
-    exit(1);
-  }
-  size_t pos = 0;
-  while (pos < size) {
-    int nbytes = write(fd, &buf[pos], size - pos);
-    if (nbytes <= 0) {
-      perror("write");
-      exit(1);
-    }
-    pos += nbytes;
-  }
-  if (close(fd) != 0) {
-    perror("close");
-    exit(1);
-  }
-  return name;
-}
-
 extern "C" int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size) {
-  char *file = buf_to_file((const char *)data, size);
-  readFileSingle(file);
-  readFileMulti(file);
-  unlink(file);
-  free(file);
+  if (size < 16) return 0;
+
+  FuzzedDataProvider stream(data, size);
+  uint64_t width = stream.ConsumeIntegral<uint64_t>();
+  uint64_t height = stream.ConsumeIntegral<uint64_t>();
+  std::vector<char> buffer = stream.ConsumeRemainingBytes<char>();
+
+  const std::string s(buffer.data(), buffer.size());
+  StdISStream is;
+  is.str(s);
+
+  readFileSingle(is, width, height);
+  readFileMulti(is);
   return 0;
 }
diff --git a/projects/openexr/openexr_deeptiles_fuzzer.cc b/projects/openexr/openexr_deeptiles_fuzzer.cc
index 4a51be115..b4f0e056f 100644
--- a/projects/openexr/openexr_deeptiles_fuzzer.cc
+++ b/projects/openexr/openexr_deeptiles_fuzzer.cc
@@ -23,6 +23,7 @@
 #include <ImfDeepTiledInputFile.h>
 #include <ImfDeepTiledInputPart.h>
 #include <ImfTiledInputPart.h>
+#include <ImfStdIO.h>
 
 namespace IMF = OPENEXR_IMF_NAMESPACE;
 using namespace IMF;
@@ -115,10 +116,10 @@ static void readFile(T *part) {
   }
 }
 
-static void readFileSingle(const char filename[]) {
+static void readFileSingle(IStream& is) {
   DeepTiledInputFile *file;
   try {
-    file = new DeepTiledInputFile(filename, 8);
+    file = new DeepTiledInputFile(is, 8);
   } catch (...) {
     return;
   }
@@ -131,11 +132,11 @@ static void readFileSingle(const char filename[]) {
   delete file;
 }
 
-static void readFileMulti(const char filename[]) {
+static void readFileMulti(IStream& is) {
   MultiPartInputFile *file;
 
   try {
-    file = new MultiPartInputFile(filename, 8);
+    file = new MultiPartInputFile(is, 8);
   } catch (...) {
     return;
   }
@@ -161,36 +162,15 @@ static void readFileMulti(const char filename[]) {
 
 }  // namespace
 
-// from cl/164883104
-static char *buf_to_file(const char *buf, size_t size) {
-  char *name = strdup("/dev/shm/fuzz-XXXXXX");
-  int fd = mkstemp(name);
-  if (fd < 0) {
-    perror("open");
-    exit(1);
-  }
-  size_t pos = 0;
-  while (pos < size) {
-    int nbytes = write(fd, &buf[pos], size - pos);
-    if (nbytes <= 0) {
-      perror("write");
-      exit(1);
-    }
-    pos += nbytes;
-  }
-  if (close(fd) != 0) {
-    perror("close");
-    exit(1);
-  }
-  return name;
-}
-
 extern "C" int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size) {
-  char *file = buf_to_file((const char *)data, size);
+
+  const std::string s(reinterpret_cast<const char*>(data), size);
+  StdISStream is;
+  is.str(s);
+
   Header::setMaxImageSize(10000, 10000);
-  readFileSingle(file);
-  readFileMulti(file);
-  unlink(file);
-  free(file);
+  readFileSingle(is);
+  readFileMulti(is);
+
   return 0;
 }
diff --git a/projects/openexr/openexr_scanlines_fuzzer.cc b/projects/openexr/openexr_scanlines_fuzzer.cc
index 214b595d8..26623a1fc 100644
--- a/projects/openexr/openexr_scanlines_fuzzer.cc
+++ b/projects/openexr/openexr_scanlines_fuzzer.cc
@@ -22,16 +22,17 @@
 #include <ImfInputPart.h>
 #include <ImfMultiPartInputFile.h>
 #include <ImfRgbaFile.h>
+#include <ImfStdIO.h>
 
 using namespace OPENEXR_IMF_INTERNAL_NAMESPACE;
 using IMATH_NAMESPACE::Box2i;
 
 namespace {
 
-static void readSingle(const char fileName[]) {
+static void readSingle(IStream& is) {
   RgbaInputFile *in = NULL;
   try {
-    in = new RgbaInputFile(fileName);
+    in = new RgbaInputFile(is);
   } catch (...) {
     return;
   }
@@ -54,10 +55,10 @@ static void readSingle(const char fileName[]) {
   delete in;
 }
 
-static void readMulti(const char fileName[]) {
+static void readMulti(IStream& is) {
   MultiPartInputFile *file;
   try {
-    file = new MultiPartInputFile(fileName);
+    file = new MultiPartInputFile(is);
   } catch (...) {
     return;
   }
@@ -98,35 +99,12 @@ static void readMulti(const char fileName[]) {
 
 }  // namespace
 
-// from cl/164883104
-static char *buf_to_file(const char *buf, size_t size) {
-  char *name = strdup("/dev/shm/fuzz-XXXXXX");
-  int fd = mkstemp(name);
-  if (fd < 0) {
-    perror("open");
-    exit(1);
-  }
-  size_t pos = 0;
-  while (pos < size) {
-    int nbytes = write(fd, &buf[pos], size - pos);
-    if (nbytes <= 0) {
-      perror("write");
-      exit(1);
-    }
-    pos += nbytes;
-  }
-  if (close(fd) != 0) {
-    perror("close");
-    exit(1);
-  }
-  return name;
-}
-
 extern "C" int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size) {
-  char *file = buf_to_file((const char *)data, size);
-  readSingle(file);
-  readMulti(file);
-  unlink(file);
-  free(file);
+  const std::string s(reinterpret_cast<const char*>(data), size);
+  StdISStream is;
+  is.str(s);
+
+  readSingle(is);
+  readMulti(is);
   return 0;
 }
diff --git a/projects/openexr/openexr_tiles_fuzzer.cc b/projects/openexr/openexr_tiles_fuzzer.cc
index 2cc8ccd7a..d473021ce 100644
--- a/projects/openexr/openexr_tiles_fuzzer.cc
+++ b/projects/openexr/openexr_tiles_fuzzer.cc
@@ -29,6 +29,7 @@
 #include <ImfTiledInputPart.h>
 #include <ImfTiledOutputPart.h>
 #include <OpenEXRConfig.h>
+#include <ImfStdIO.h>
 
 using namespace OPENEXR_IMF_INTERNAL_NAMESPACE;
 using IMATH_NAMESPACE::Box2i;
@@ -49,10 +50,10 @@ void readImageONE(TiledRgbaInputFile *in, int dwx, int dwy) {
   }
 }
 
-void readImageONE2(const char fileName[]) {
+void readImageONE2(IStream& is) {
   MultiPartInputFile *in;
   try {
-    in = new MultiPartInputFile(fileName);
+    in = new MultiPartInputFile(is);
   } catch (...) {
     return;
   }
@@ -140,13 +141,13 @@ void readImageRIP(TiledRgbaInputFile *in, int dwx, int dwy) {
 
 }  // namespace
 
-static void fuzzImage(const char filename[]) {
+static void fuzzImage(IStream& is) {
   Header::setMaxImageSize(10000, 10000);
   Header::setMaxTileSize(10000, 10000);
 
   TiledRgbaInputFile *in;
   try {
-    in = new TiledRgbaInputFile(filename);
+    in = new TiledRgbaInputFile(is);
   } catch (...) {
     return;
   }
@@ -158,39 +159,16 @@ static void fuzzImage(const char filename[]) {
   readImageMIP(in, dwx, dwy);
   readImageRIP(in, dwx, dwy);
   readImageONE(in, dwx, dwy);
-  readImageONE2(filename);
+  readImageONE2(is);
 
   delete in;
 }
 
-// from cl/164883104
-static char *buf_to_file(const char *buf, size_t size) {
-  char *name = strdup("/dev/shm/fuzz-XXXXXX");
-  int fd = mkstemp(name);
-  if (fd < 0) {
-    perror("open");
-    exit(1);
-  }
-  size_t pos = 0;
-  while (pos < size) {
-    int nbytes = write(fd, &buf[pos], size - pos);
-    if (nbytes <= 0) {
-      perror("write");
-      exit(1);
-    }
-    pos += nbytes;
-  }
-  if (close(fd) != 0) {
-    perror("close");
-    exit(1);
-  }
-  return name;
-}
-
 extern "C" int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size) {
-  char *file = buf_to_file((const char *)data, size);
-  fuzzImage(file);
-  unlink(file);
-  free(file);
+  const std::string s(reinterpret_cast<const char*>(data), size);
+  StdISStream is;
+  is.str(s);
+
+  fuzzImage(is);
   return 0;
 }